Why are Plums never mentioned as a fruit beer derivative?

I am about to brew a fruit beer and good old Watties NZ plums seem like a good option, just in juice and no preservatives from what I can see. Good sugar content compared with peaches or raspberries. Is there any reason why I shouldn't use these? The recipe on the Blackrock site says to add all fruit (cherries) at the beginning but I am of the opinion that 95% fermenting the base and then racking onto the prepped fruit is the way to go. I planned to remove the stones and puree with a sterilised stick blender. A couple of questions:

1. How much fruit for a 5 gal brew (starting with hopped wheat extract 1.7kg and 1kg dextrose)

2. Should I boil the fruit first or will it be fine just pureed from the tin ?

3. Can I expect bottling issues with the sediment or is it advisable to rack a second time prior to bottling? 

Thanks, dumb questions will cease at this time.